diff --git a/src/cli/commands/mcp.ts b/src/cli/commands/mcp.ts
index b2a66c0..f718427 100644
--- a/src/cli/commands/mcp.ts
+++ b/src/cli/commands/mcp.ts
@@ -19,12 +19,19 @@ import { flagValue, hasFlag } from '../flags.js';
 
 const SERVER_NAME = 'memoryd';
 
-/** The config entry every client receives. */
-const SERVER_ENTRY = {
-  command : SERVER_NAME,
-  args    : ['serve', '--stdio'],
-  env     : {},
-};
+/** Build the config entry, prompting for password if needed. */
+function serverEntry(): Record<string, unknown> {
+  const password = process.env.MEMORYD_PASSWORD;
+  const env: Record<string, string> = {};
+  if (password) {
+    env.MEMORYD_PASSWORD = password;
+  }
+  return {
+    command : SERVER_NAME,
+    args    : ['serve', '--stdio'],
+    env,
+  };
+}
 
 // ---------------------------------------------------------------------------
 // Client definitions
@@ -93,7 +100,7 @@ function writeJsonConfig(path: string, config: McpConfig): void {
 function addServerToConfig(path: string): void {
   const config = readJsonConfig(path);
   config.mcpServers = config.mcpServers ?? {};
-  config.mcpServers[SERVER_NAME] = SERVER_ENTRY;
+  config.mcpServers[SERVER_NAME] = serverEntry();
   writeJsonConfig(path, config);
 }
 
@@ -178,12 +185,28 @@ function uninstallProject(): void {
 function printConfig(): void {
   const config = {
     mcpServers: {
-      [SERVER_NAME]: SERVER_ENTRY,
+      [SERVER_NAME]: serverEntry(),
     },
   };
   console.log(JSON.stringify(config, null, 2));
 }
 
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+/** Warn if MEMORYD_PASSWORD is not set after install. */
+function warnIfNoPassword(): void {
+  if (!process.env.MEMORYD_PASSWORD) {
+    console.log('');
+    console.log(
+      'Warning: MEMORYD_PASSWORD is not set. Add it to your MCP client\'s env '
+      + 'config or memoryd will prompt for a password on stdin '
+      + '(incompatible with stdio transport).',
+    );
+  }
+}
+
 // ---------------------------------------------------------------------------
 // Public command
 // ---------------------------------------------------------------------------
@@ -225,6 +248,7 @@ async function mcpInstall(args: string[]): Promise<void> {
   const scope = flagValue(args, '--scope');
   if (scope === 'project') {
     installProject();
+    warnIfNoPassword();
     return;
   }
 
@@ -241,6 +265,7 @@ async function mcpInstall(args: string[]): Promise<void> {
     }
     client.install();
     console.log(`Installed memoryd in ${client.label}.`);
+    warnIfNoPassword();
     return;
   }
 
@@ -264,6 +289,8 @@ async function mcpInstall(args: string[]): Promise<void> {
       console.error(`Failed to install in ${client.label}: ${msg}`);
     }
   }
+
+  warnIfNoPassword();
 }
 
 // ---------------------------------------------------------------------------
diff --git a/src/cli/main.ts b/src/cli/main.ts
index 35534e3..4514ddf 100644
--- a/src/cli/main.ts
+++ b/src/cli/main.ts
@@ -153,13 +153,20 @@ async function main(): Promise<void> {
   const passwordFlag = flagValue(rest, '--password');
   const password = await getPassword(passwordFlag);
 
-  const { resolveProfile, profileDataPath } = await import('../profiles/config.js');
+  const { resolveProfile, profileDataPath, profilesDir } = await import('../profiles/config.js');
   const profileFlag = flagValue(rest, '--profile');
   const profileName = resolveProfile(profileFlag);
   const dataPath = profileName ? profileDataPath(profileName) : undefined;
 
+  // Derive a per-profile sidecar path so different identities don't
+  // cross-contaminate the search index.
+  const { resolveConfig } = await import('../config.js');
+  const config = profileName
+    ? resolveConfig({ sidecarPath: join(profilesDir(), profileName, 'index.db') })
+    : resolveConfig();
+
   const { connectAgent } = await import('./agent.js');
-  const ctx = await connectAgent({ password, dataPath });
+  const ctx = await connectAgent({ password, dataPath, config });
   const json = hasFlag(rest, '--json');
 
   switch (command) {
diff --git a/tests/cli/mcp.spec.ts b/tests/cli/mcp.spec.ts
index 897f284..014c4ca 100644
--- a/tests/cli/mcp.spec.ts
+++ b/tests/cli/mcp.spec.ts
@@ -60,6 +60,68 @@ describe('mcp install/uninstall', () => {
     });
   });
 
+  // -------------------------------------------------------------------------
+  // password in env
+  // -------------------------------------------------------------------------
+
+  describe('password inclusion', () => {
+    const origPassword = process.env.MEMORYD_PASSWORD;
+
+    afterEach(() => {
+      if (origPassword !== undefined) {
+        process.env.MEMORYD_PASSWORD = origPassword;
+      } else {
+        delete process.env.MEMORYD_PASSWORD;
+      }
+    });
+
+    it('includes MEMORYD_PASSWORD in config when set', async () => {
+      process.env.MEMORYD_PASSWORD = 'test-secret';
+      const { mcpCommand } = await import('../../src/cli/commands/mcp.js');
+      const lines = await captureLog(() => mcpCommand(['install', '--print']));
+      const json = JSON.parse(lines.join('\n'));
+      expect(json.mcpServers.memoryd.env.MEMORYD_PASSWORD).toBe('test-secret');
+    });
+
+    it('omits MEMORYD_PASSWORD from config when not set', async () => {
+      delete process.env.MEMORYD_PASSWORD;
+      const { mcpCommand } = await import('../../src/cli/commands/mcp.js');
+      const lines = await captureLog(() => mcpCommand(['install', '--print']));
+      const json = JSON.parse(lines.join('\n'));
+      expect(json.mcpServers.memoryd.env.MEMORYD_PASSWORD).toBeUndefined();
+    });
+
+    it('warns when MEMORYD_PASSWORD is not set after install', async () => {
+      delete process.env.MEMORYD_PASSWORD;
+      const origCwd = process.cwd();
+      const projectDir = join(TEST_DIR, 'pw-warn-project');
+      mkdirSync(projectDir, { recursive: true });
+      process.chdir(projectDir);
+      try {
+        const { mcpCommand } = await import('../../src/cli/commands/mcp.js');
+        const lines = await captureLog(() => mcpCommand(['install', '--scope', 'project']));
+        expect(lines.some(l => l.includes('Warning: MEMORYD_PASSWORD is not set'))).toBe(true);
+      } finally {
+        process.chdir(origCwd);
+      }
+    });
+
+    it('does not warn when MEMORYD_PASSWORD is set', async () => {
+      process.env.MEMORYD_PASSWORD = 'test-secret';
+      const origCwd = process.cwd();
+      const projectDir = join(TEST_DIR, 'pw-nowarn-project');
+      mkdirSync(projectDir, { recursive: true });
+      process.chdir(projectDir);
+      try {
+        const { mcpCommand } = await import('../../src/cli/commands/mcp.js');
+        const lines = await captureLog(() => mcpCommand(['install', '--scope', 'project']));
+        expect(lines.some(l => l.includes('Warning: MEMORYD_PASSWORD is not set'))).toBe(false);
+      } finally {
+        process.chdir(origCwd);
+      }
+    });
+  });
+
   // -------------------------------------------------------------------------
   // --scope project
   // -------------------------------------------------------------------------
diff --git a/tests/config.spec.ts b/tests/config.spec.ts
index 0632300..d8ffdff 100644
--- a/tests/config.spec.ts
+++ b/tests/config.spec.ts
@@ -103,4 +103,14 @@ describe('resolveConfig', () => {
     expect(config.port).toBe(5000);
     expect(config.host).toBe('0.0.0.0');
   });
+
+  it('accepts per-profile sidecar path override', () => {
+    const config = resolveConfig({
+      sidecarPath: '/home/user/.enbox/profiles/alice/index.db',
+    });
+    expect(config.sidecarPath).toBe('/home/user/.enbox/profiles/alice/index.db');
+    // Other defaults still apply.
+    expect(config.embedding.provider).toBe('noop');
+    expect(config.port).toBe(3200);
+  });
 });